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Results for “Genetic Linkage”

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At least 37 records · Page 2Linked to original sources
PubMed1977

Probable genetic linkage between autosomal dominant retinitis pigmentosa (RP) and amylase (AMY2): evidence of an RP locus on chromosome 1.

A linkage analysis is reported for three branches of a single family segregating for autosomal dominant retinitis pigmentosa. A statistically significant lod score of 3.9 is obtained for the RP locus and AMY2 at a recombination frequency of 1%. This linkage indicates that the RP locus is on the no. 1 chromosome since the AMY2 locus has been placed on the short arm of 1. Lod scores are reported for four other loci on chromosome 1; none of these achieve statistical significance. Analyses are reported for 23 additional autosomal markers and close linkage with RP can be excluded for a number of these.

Amylases↗
PubMed1977

Inherited polymorphism of guinea pig factor B and C4: evidence for genetic linkage between the C4 and Bf loci.

An inherited structural polymorphism of the guinea pig complement protein C4 and of factor B of the alternative pathway was demonstrated by use of high voltage agarose electrophoresis combined with a subsequent immunofixation technique. No polymorphism of guinea pig C3 could be shown. Three common allelic genes were proven to code for C4-S, C4-S1, and C4-F, respectively. Two common allelic genes are responsible for the Bf-F and Bf-S phenotype expression. A strong linkage disequilibrium between both C4 and Bf was demonstrated.

Animals↗
PubMed1978

Genetic control of the immune response to the H-2Dk private specificity, H-2.32. II. Genetic linkage analysis of a backcross generation.

B10.AKM mice (H-2M) when immunized with H-2k cells showed very low cytotoxic antibody responses to the H-2Dk private specificity H-2.32, whereas AKR.M and (AKR.M X B10.AKM)F1 mice that possess the same H-2m haplotype mounted reasonable anti-H-2.32 antibody responses. The genetic nature of the non-H-2 linked gene(s) controlling the anti-H-2.32 response was analyzed on the backcross progeny raised between (AKR.M X B10.AKM)F1 and B10.AKM mice. The anti-H-2.32 antibody response was found to be predominantly controlled by a single locus. This locus segregated independently of the Ig heavy chain locus, the Ly2 locus, and the Mls locus. Despite the observed difference in antibody production, no significant differences between AKR.M and B10.AKM mice were detected in induction of H-2Dk-specific killer T cells. Thus, the defect in the response of B10.AKM mice to H-2.32 can be detected at the level of B cell function and is controlled by a single non-H-2-linked genetic locus, but is not attributable to genes linked to the major immunoglobulin structural genes nor to the Mls locus.

Animals↗
PubMed1979

Genetic linkage between hereditary hemochromatosis and HLA.

A large Mormon pedigree of a proband with hemochromatosis was studied, using transferrin saturation as the quantitative phenotypic trait. The analysis indicated that the inheritance of hemochromatosis was recessive, with partial expression in some heterozygotes. The lod score of 6.88 (theta = .0) was strongly indicative of linkage between the hemochromatosis locus and the human major histocompatibility (HLA) loci.

Chromosome Mapping↗
PubMed1977

The Lutheran and secretor loci: genetic linkage analysis.

Linkage analysis of Lu and Se and 31 other loci indicate that Lu:Se are not closely linked to ABO, ACP1, Co, Do, Est.D,Fy, GC, Gm, GLO:HLA, GPT, Inv, Jk,K,MN,P,PGD,PGM1, Rh,Sc, UMPK OR Yt. Lod scores for 18 families informative for Lu:Se gave no evidence for sex differentiation in recombination fraction: theta for males was 0.07, and for females, .08.

Adolescent↗
PubMed1979

Genetic linkage analysis of hemoglobin variants in 175 families.

Linkage analysis using the LIPED program developed by Ott for the analysis of whole family data was performed on 175 families with variants of the hemoglobin beta- or gamma-chain. Comparison of our results with those in the literature indicate that there is little evidence for linkage with any of the currently used markers, although there is considerable heterogeneity in lod scores between sexes for the Duffy and MNS blood groups. It is suggested that the most successful approach in the future will be to analyze markers known to be localized on chromosomes which have been indicated as likely sites of the beta-chain locus from hybridization studies.

Duffy Blood-Group System↗
PubMed1978

[Genetic linkage of HLA-Bf. Study of 19 informative families].

Since the discovery of the linkage between HLA and Bf by Allen in 1974 several reports have shown a very close linkage between Bf and HLA-B. We have studied 19 families with 81 offsprings for the linkage between HLA (A,B) and Bf. The total "lod scores" in our material for the linkage between HLA-B and Bf is 17,167 at theta = 0.00. No recombination was observed between HLA-B and Bf. One recombination out of 79 informative meiotic divisions was observed between HLA-A and Bf. This result would mean that the Bf locus is about 1.3% recombination fraction far from the HLA-A locus. Our estimation is in good agreement with the results of other authors. However the estimation of recombination fractions is only an arbitrary mean to map genetic loci on chromosomal regions and family studies of cases with intra-HLA cross-overs are of more interest. All available data from the litterature are in favour to a very close linkage between Bf and HLA-B and to a situation of the Bf locus between HLA-B and HLA-D. However some conflicting data on Bf gene mapping have been published. More precise informations may be obtained as soon as a more exact structure of the HLA region, in particular of the HLA-D region, will be known.

Adult↗
PubMed2024

Genetic linkage disequilibrium of deleterious mutations in threatened mammals.

The impact of negative selection against deleterious mutations in endangered species remains underexplored. Recent studies have measured mutation load by comparing the accumulation of deleterious mutations, however, this method is most effective when comparing within and between populations of phylogenetically closely related species. Here, we introduced new statistics, LDcor, and its standardized form nLDcor, which allows us to detect and compare global linkage disequilibrium of deleterious mutations across species using unphased genotypes. These statistics measure averaged pairwise standardized covariance and standardize mutation differences based on the standard deviation of alleles to reflect selection intensity. We then examined selection strength in the genomes of seven mammals. Tigers exhibited an over-dispersion of deleterious mutations, while gorillas, giant pandas, and golden snub-nosed monkeys displayed negative linkage disequilibrium. Furthermore, the distribution of deleterious mutations in threatened mammals did not reveal consistent trends. Our results indicate that these newly developed statistics could help us understand the genetic burden of threatened species.

Animals↗
PubMedDate not supplied

Close genetic linkage between HLA and congenital adrenal hyperplasia (21-hydroxylase deficiency).

Congenital adrenal hyperplasia (C.A.H.) with 21-hydroxylase deficiency is an autosomal recessive disease. HLA genotyping of parents and children in six families in which more than 1 child had C.A.H. established that the gene responsible for 21-hydroxylase deficiency is closely linked to HLA. One patient had inherited a maternal HLA-A/B recombinant haplotype and studies in this family indicated that the abnormal gene is close to the HLA-B locus. The findings provide a method for identification of C.A.H. carriers and for prenatal diagnosis of affected children.

Adrenal Hyperplasia, Congenital↗